Inhalation therapy apparatus having a valve for limiting the inspiration flow

ABSTRACT

In an inhalation therapy apparatus a limiter section is provided in the air supply duct which serves as the limiting element for the movement of a valve element of an inlet valve. In the limiter section are provided openings through which surrounding air can flow when the valve element rests against the front edge of the limiter section facing the valve element.

[0001] The present invention concerns an inhalation therapy apparatusand in particular a valve for limiting the inspiration flow in aninhalation therapy apparatus.

[0002] From EP-B-0 281 650 is known an aerosol atomiser which consistsof an essentially cylindrical main body in which is arranged an atomisernozzle for atomising an aerosol and into which projects an air supplyduct for the supply of the surrounding air. The external opening of theair supply duct is closed by an inlet valve which is constructed as aone-way valve. It allows the inflow of surrounding air into thenebuliser housing when a patient inhales through a mouth piece of theaerosol atomiser but prevents the aerosol from escaping from theinternal chamber of the atomiser during pauses in the breathing and inthe event of the patient breathing into the aerosol atomiser duringexhalation. The known inhalation therapy apparatus accordingly isconstructed in such a way that the patient can breathe in any desiredvolume of air, limited only by the flow resistance determined by theshape of the atomiser. This flow resistance as a rule is not however ofany consequence to the inspiration flow of up to 100 l/min reached by apatient.

[0003] From EP-A-0 895 788 is known a valve for providing a freelypredetermined limitation of the inspiration flow, so that the patientduring inhalation can breathe in without any significant flow resistanceonly until reaching a maximum inspiration flow (threshold value) e.g. ofapproximately 30 l/min. On reaching or exceeding the threshold value,the movement of the valve element provided in the inlet valve is limitedto such an extent that an increased flow resistance is set up. In theinhalation therapy apparatus according to the EP-A-0 895 768 this isachieved in that opposite to the valve element provided for closing theinhalation openings there is provided a limiting element against whichthe valve element rests when the inspiration flow of the patient exceedsthe threshold value. The valve element then closes a large part of theopenings which are present in the limiting element and permits theflowing through of the breathed in surrounding air only through verymuch smaller openings, thus increasing the flow resistance to theinhalation. The limiting element in the inhalation therapy apparatusaccording to the EP-A-0 895 788 is an additional component which has tobe fitted in the vicinity of the valve element, especially after eachcleaning process of the inlet valve by the patient.

[0004] With this prior art in the background it is the aim of thisinvention to further improve the known inhalation apparatus.

[0005] Achieved is this aim in that the invention proposes an embodimentwhich for the patient is easier to handle, as the separately to handlelimiting element is made obsolete. Through the invention the patient isprovided with an inhalation therapy apparatus which is improved with aview to handling.

[0006] As described in patent claim 1, the inhalation therapy apparatusaccording to the invention is characterised by the fact that thelimiting element is attached to the air supply duct and preferablyintegrated with the same, in particular is constructed as a one-pieceextension of the air supply duct in the direction of the valve element.Apart from that, the limiter section of the air supply duct has airinhalation openings through which, on exceeding the inspiration flowthreshold value, the inhaled surrounding air substantially flows.

[0007] Advantageous embodiments are disclosed in the sub-claims. Thefollowing embodiment example is described in more detail with the aid ofdrawings, these show:

[0008]FIG. 1 an inhalation therapy apparatus with an inlet valve and alimiting element according to the invention;

[0009]FIG. 2A-2C the inlet valve and limiting element according to theinvention in various detailed views; and

[0010]FIG. 3 a sectional view of the inlet valve and the limitingelement according to the invention.

[0011] In FIG. 1 is shown an inhalation therapy apparatus which consistsof a cylindrical main body 1 and a connecting piece 2 formed thereto.Inside the cylindrical main body, i.e. in the nebuliser chamber 1 a, isarranged an atomiser nozzle 1 b (see for example EP-B-0 281 650) whichproduces an aerosol from a medicine stored in the inhalation therapyapparatus. For this the atomiser nozzle 1 b is supplied with compressedair via a pressure medium pipe 3. In the connecting piece 2 is normallyarranged a mouthpiece or mask through which the patient can breathe inthe aerosol produced in the nebuliser chamber. From the top end of thecylindrical main body 1 in FIG. 1 a cylindrical air supply duct 1 cprojects into the nebuliser chamber. Through this air supply duct 1 cthe surrounding air can continue to flow into the interior 1 a of theinhalation therapy apparatus when the patient breathes in the aerosolvia the connecting piece 2. On the outward pointing opening of the airsupply duct 1 c is provided a passive inlet valve 4 which is constructedas a one-way valve and whose make-up is described in more detail in thefollowing with reference to FIG. 2.

[0012]FIG. 2A shows the passive inlet valve 4 from the side facingoutwards, i.e. from the side which can also be seen in FIG. 1. FIG. 2Bshows the passive inlet valve 4 on the side facing the air supply ductwhich is not visible in FIG. 1. FIG. 2C shows a cross-section throughthe passive inlet valve 4 along the line A-A in FIG. 2B in a conditionmounted in an inhalation therapy apparatus.

[0013] In FIG. 2A to FIG. 2C it can be seen that the passive inlet valve4 of the here described embodiment example of the invention consists ofa cylindrical main body 10 with a surface area formed in several stepsand a closure wall 11 running perpendicular to the cylinder axis. In theclosure wall 11 are provided a plurality of air inlet openings 12 whichcan also be described as through openings and through which surroundingair can flow into the interior of the inhalation therapy apparatus. Inthe cylinder section 10 a with the smallest outer diameter is arranged avalve element 13 which has the form of a small circular valve plate witha central securing opening. The small valve plate 13 consists of anelastic material, for example silicon, with a sufficient inherentstiffness which in the non-deflected rest position allows the smallvalve plate 13 to shut the air inlet openings 12 of the limiting valve4, at least when the patient exhales into the inhalation therapyapparatus. As shown in FIG. 2C, a continuous circular sealing lip 14 canbe additionally provided on the side of the closure wall 11 facing thesmall valve plate. The small valve plate 13 for securing is mounted on apin 15 extending along the cylinder axis on the side of the inlet valve4 facing the interior chamber 1 a of the inhalation therapy apparatus.

[0014] This construction functions as follows. When the patient inhalesthrough the inhalation therapy apparatus, the small valve plate 13 isdeflected inwards and thus allows additional air to flow through the airinlet openings 12 of the inlet valve 4. The opening cross-section thuscreated is substantially proportional to the underpressure built up inthe nebuliser chamber. During pauses in breathing or at least duringexhalation by the patient into the inhalation therapy apparatus, thevalve element 13 shuts the openings 12.

[0015] As can be seen from FIG. 2C, according to the invention the airsupply duct 1 c at the end opposite the small valve plate 13 isconstructed in such a way that it extends into the direct proximity ofthe small valve plate 13 and assumes the function of a limiting element.This means that the limiter section 1 d of the air supply duct 1 climits the deflection of the small valve plate 13. The size of the smallvalve plate 13 is therefore selected to be such that it rests on thefront edge 1 e of the limiter section 1 d of the air supply duct 1 cwhen the inspiration flow, caused by the inhalation of the patient,exceeds a threshold value of for example approximately 30 l/min. Forthis the diameter of the valve element 13 is preferably larger but atleast equal to the diameter of the limiter section 1 d. The thresholdvalue can be determined by the distance between the valve element andthe edge 1 e on the front side. The limiter section 1 d of the airsupply duct has air throughput openings 17 which are so arranged that aflow-through of the sucked in air can still be possible even when thevalve element 13 rests on the edge 1 e of the front side. However, thesize of the air throughput openings 17 are selected in such a way that,when the valve element 13 rests on the front edge 1 e of the limitersection 1 d of the air supply duct 1 c, a flow resistance is producedwhich the patient can sense. The size of the air throughput openings 17also has an influence on the threshold value for the maximum inspirationflow.

[0016] So long as the patient inhales within the pressure/flow rangewhich is desirable in an aerosol physical sense, for example aninspiration flow below 30 l/min, the flow resistance, which is opposedby the inhalation through the inhalation therapy apparatus, is low andhardly affects the inhalation process of the patient. If the inspirationflow increases over the given threshold value, i.e. if the patient doesnot breathe within a pressure/flow range which is not desirable in anaerosol physical sense, the the small valve plate 13 rests against thefront edge 1 e of the limiter section 1 d of the air supply duct 1 c,which causes the air supply duct to be closed on the front side and theinhaled surrounding air is forced to flow through the air throughputopenings 17 in the limiter section 1 d of the air supply duct 1 c. Thethus increased flow resistance which is clearly felt by the patientcauses the patient to reduce the inspiration flow, so that it dropsagain below the threshold value, which leads to the valve element 13being raised from the front edge 1 e of the limiter section 1 d of theair supply duct 1 c. The embodiment of the inhalation therapy apparatusaccording to the invention finally has the effect that the patientbreathes within the pressure/flow range which is desirable in theaerosol physical sense.

[0017] As already shown in FIG. 2C, the air throughput openings 17 aresignificantly smaller than the cross-section of the air supply duct 1 c.The form of the air throughput openings 17 is arbitrary. In FIG. 2C areshown slot-like air throughput openings. The air throughput openings 17may also be quadratic, semi-circular or triangular-shaped recesses whichextend to the front edge 1 e of the limiter section 1 d of the airsupply duct 1 c. For forming the air throughput openings 17 the edge 1 emay be constructed completely or partly in undulating or zigzag shape.However, the air throughput openings 17 may also be constructed in sucha way that they do not extend to the edge 1 e but may be constructed asopenings in the limiter section 1 d of the air supply duct 1 c. Theshape and the number in both cases may be selected in accordance withthe application and demands of the inlet valve or the inhalation therapyapparatus.

[0018] The limiter section 1 d may, however, also be constructed as aseparate part of the inhalation nebuliser according to the invention tobe inserted into the air supply duct. Such an embodiment of the limitersection 1 d of the air supply duct 1 c is shown in FIG. 3. As can beseen in this figure, the limiter section 1 d is constructed as acylinder shell which in at least sections of its outer casing hassnap-in projections 20 which can be snapped in to correspondingly shapedsnap-in notches 21. The snap-in notches are constructed as continuousgrooves running along the inner surface of the air supply duct 1 c. Inthe example shown in FIG. 3 the grooves are wedge-shaped. The snap-inprojections 20 on the limiter section 21 also can be constructed ascontinuously running snap-in projection. However, the construction mustbe such that the limiter section 1 d can be inserted into the air supplyduct 1 c. However, this can be easily achieved by a correspondingdimensioning and shaping of the snap-in projections 20 in relation tothe snap-in notches 21. The limiter section 1 d can then be arranged indifferent snap-in positions in the air supply duct 1 c. With the aid ofthe snap-in means it is therefore possible to flexibly adjust thedistance d between the front edge 1 e of the limiter section 1 d and thevalve element 13. The distance d however determines the threshold valueat which the valve element 13 reaches the front edge 1 e of the limitersection 1 d and rests on it. In this embodiment example the valveelement 13 has a larger diameter than the limiter section 1 d.

[0019] In the embodiment example shown in FIG. 3 the air throughputopenings 17 are wedge-like and extend to the edge 1 e on the front side.

[0020] The inhalation therapy apparatus according to the invention ischaracterised by the fact that the limiter element is arranged in theair supply duct 1 c, preferably constructed in one piece with the airsupply duct. This has the effect that after removal of the inlet valve,easily to handle components of the inhalation therapy apparatusaccording to the invention are exposed. In particular the possibility ofcleaning the inlet valve is significantly improved. The integralembodiment of the limiter section and the air supply duct reducesfurther the number of parts handled by the patient, which furthersimplifies the handling of the inhalation therapy apparatus according tothe invention.

1. Inhalation therapy apparatus having a nebuliser chamber (1 a) inwhich with the aid of an atomiser nozzle (1 b) an aerosol is produced, aconnecting piece (2) through which the aerosol is discharged from thenebuliser chamber (1 c), an air supply duct (1 c) through which thesurrounding air enters the nebuliser chamber (1 a), and an inlet valve(4) which is arranged at one end of the air supply duct (1 c) and whichcomprises at least one inlet opening (12) and one valve element (13)closing the inlet opening and which is arranged in the air supply duct(1 c) in such a way that an underpressure in the nebuliser chamber (1 a)moves the valve element (1 c) in order to free the inlet opening (12),characterised in that in the air supply duct (1 c) is provided a limitersection (1 d) which restricts the movement of the valve element (13) insuch a way that the freeing of the inlet opening (12) is essentiallyproportional to the underpressure only up to a threshold value of theunderpressure in the nebuliser chamber (1 a).
 2. Inhalation therapyapparatus according to claim 1, characterised in that the limitersection (1 d) is constructed to be integral with the air supply duct (1c).
 3. Inhalation therapy apparatus according to claim 1, characterisedin that the limiter section (1 d) can be inserted into the air supplyduct (1 c).
 4. Inhalation therapy apparatus according to claim 3,characterised in that limiter section (1 d) has snap-in projections (20)which in the snap-in condition engage with snap-in notches (21) in theair supply duct (1 c).
 5. Inhalation therapy apparatus according toclaim 4, characterised in that snap-in projections (20) and the snap-innotches (21) are constructed in such a way that the distance between thean edge of the limiter section (1 d) facing the valve element (13) andthe valve element (13) can be adjusted.
 6. Inhalation therapy apparatusaccording to one of the claims 1 to 5, characterised in that the limitersection (1 d) has openings (17).
 7. Inhalation therapy apparatusaccording to claim 6, characterised in that the openings (17) extend upto the edge (1 c), facing the valve element, of the limiter section (1d) of the air supply duct (1 c).
 8. Inhalation therapy apparatusaccording to one of the claims 1 to 7, characterised in that the limitersection (1 d) of the air supply duct (1 c) is constructed in such a waythat the valve element (13) does not rest against the edge (1 e) of thelimiter section (1 d) of the air supply duct (1 c) until a freelyadjustable maximum inspiration flow of preferably 20 to 40 l/min,especially approximately 30 l/min is achieved.
 9. Inhalation therapyapparatus according to one of the claims 1 to 8, characterised in thatthe limiter section (1 d) has a cylindrical basic shape whichsubstantially corresponds to the cylindrical form of the air supply duct(1 c).
 10. Inhalation therapy apparatus according to claim 9,characterised in that the diameter of the limiter section (1 d) of theair supply duct (1 c) is substantially equal to the diameter of the airsupply duct (1 c).
 11. Inhalation therapy apparatus according to one ofthe claims 1 to 10, characterised in that the valve element (13) ismanufactured from silicon or another elastic material.
 12. Inhalationtherapy apparatus according to one of the claims 1 to 11, characterisedin that the diameter of the valve element (13) is bigger than thediameter of the limiter section (1 d).